Copper Bio recovery from Industrial Wastewater Using Microbial Biofilms

Mechanisms of water decontamination often exploit bacterial exopolymeric substances (EPS) as active surfaces for binding heavy metals (HM) cations. Biofilm formation on microporous carriers inoculated with specific metal-resistant bacterial strains, represent an operationally advantageous approach compared to planktonic systems in wastewater treatment. This study investigates the feasibility of using a copper-resistant strain, Serratia plymuthica As3-5a(5) (MIC of 8 mM), in a biofilm-based system to remove Cu(II) from electroplating wastewaters. This strain, in non-proliferating cell planktonic system, achieved up to 92% removal of Cu(II) from a 3 mM solution and 97% removal from Cu-contaminated (39 mM) electroplating wastewater within 4 minutes contact time. In biofilm-based systems, the strain demonstrated Cu(II) removal efficiencies of 42% with calcium alginate beads, 55% with perlite gardening substrate, and 92% with sintered glass beads. These findings suggest that S. plymuthica As3-5a(5) holds significant potential for the development of systems for industrial wastewater decontamination.